Wheel damage contributes a great deal to maintenance costs associated with railway freight cars. Unreleased handbrakes contribute to most damage on freight car wheels. That is, if the handbrake is left in the applied position and an engine then pulls the railway car, the wheel will not rotate thereby causing flat spots to form on the area of the wheel in contact with the rail.
It is well known in the art of railroad cars to equip railcars with a manual brake system that is actuated by a manually turned wheel. The wheel is attached through gearing to an axle by a chain running down the front of the car, the other end of the chain being connected to the brake rigging. Turning of the wheel gathers the chain, putting it in tension, thereby causing the brake pads to contact the wheel. Prior art systems also use quick release handbrakes to release the brakes. However, one problem with these systems is that it is difficult to detect if the brake system is actually fully released.
One way to ensure that a brake system is released is to detect when the brake is in the fully released position. Several methods have been suggested for sensing when a freight car hand brake is fully released such as those systems described in U.S. Pat. Nos. 6,170,619, 6,237,722 and 6,364,069. However, these solutions present additional problems and fail to provide an automated brake release solution.